The present invention relates to a peripheral protection device for two metal pieces fitted into one another and having a general flange shape, the first of which has an edge extending outwards and the second of which has a marginal zone, a first part of which has substantially the form of a capital S whose vertical axis is substantially parallel to the edge and a second part of which is substantially perpendicular to the edge.
These metal pieces are, for example, those used in order to construct a depression servomotor generally employed in power-assisted braking in motor vehicles.
The documents EP-A-0,072,602 and EP-A-0,300,857 describe such servomotors.
The place reserved for the servomotor in the vehicle thus equipped is often very small and bundles of electrical cables may be disposed in the immediate vicinity thereof.
In this case, the vibrations inherent in the vehicle can cause wearing of the cables and, consequently, cause the exposure of a conducting core which has an electrical voltage which is different from that of the servomotor. It is thus necessary to equip the servomotor with a protection device which tends to avoid such wear.
In this case, a person skilled in the art generally disposes an insulating film by adhesive bonding on the corresponding part of the servomotor. However, such a film has the disadvantage of ageing unsatisfactorily due to its environment and of rapidly becoming detached.